Brown ghost electric fishes of the Apteronotus leptorhynchus species‐group (Ostariophysi,Gymnotiformes); monophyly,major clades,and revision

Neotropical brown ghost electric knifefishes of the Apteronotus leptorhynchus species‐group are reviewed. A series of synapomorphies delimit the species‐group and the two major subunits that comprise that clade. The phylogeny is concordant with the hypothesis of a primary division within the clade resultant from Andean uplift events 8 Mya and with the existence of ancestral components of the species‐group 12 Mya. Species of the species‐group are characterized by morphological stasis across that time frame. Apteronotus leptorhynchus, previously considered to be a widely distributed and morphologically variable species, was found to encompass five species. The description of the four new species is supplemented by the redescription of the five previously recognized forms within the species‐group. Members of this clade are broadly distributed through the Essequibo River and Río Orinoco of the Atlantic slope of South America, the Ríos Aroa, Atrato, Cauca, Magdalena, and Yaracuy, and the rivers of the Lago Maracaibo basin of the Caribbean slope and drainages in northern Colombia and Panama along the Pacific versant. © 2013 The Linnean Society of London